Of the DNA viruses, the herpes group is the source of the most common viral illnesses in man. The group consists of herpes simplex virus (HSV) type I and II, varicella zoster (VZV) Epstein-Barr virus (EBV) and cytomegalovirus (CMV).
As with other herpes viruses, infection with CMV leads to a lifelong association of virus and host. Following a primary infection, virus may be shed for a number of years. Infection in otherwise healthy individuals is frequently asymptomatic, as 80% of the adult population harbor the virus in latent form. In immunocompromised individuals, such as chemotherapy patients, organ transplant patients and in particular AIDS sufferers, latent CMV can be re-activated resulting in microcephaly, hepatosplenomegaly, jaundice, convulsive seizures which may cause mental retardation, mononucleosis, retinitis and even death. In AIDS patients, CMV is a predominant cause of morbidity.
A variety of drugs have been developed to treat herpesvirus infection, including naturally occurring proteins and synthetic nucleoside analogs. For example, the natural antiviral protein, interferon, has been used in the treatment of herpesvirus infections, as have the nucleoside analogs, cytosine-arabinoside, adenine-arabinoside, iodoxyuridine and acyclovir, which is presently the treatment of choice for herpes simplex type I infection.
Unfortunately, drugs such as acyclovir that have proven effective to treat certain herpesviruses infections are not sufficiently effective of treat CMV. And, drugs currently used to treat CMV infection, such as ganiciclovir (9-(1,3-dihyroxy-2-propoxy)methyl!guanine) and foscarnet (phosphonoformic acid), lack the acceptable side effect and safety profiles of the drugs approved for treatment of other herpesviruses.
Thus, there remains a need for therapeutic and prophylactic non-nucleoside agents effective to treat CMV infection. Accordingly, it is an object of the present invention to provide a method of inhibiting CMV replication in a mammal. It is also an object of the present invention to provide compounds and pharmaceutical compositions useful for inhibiting CMV replication in a mammal.